Geoscience Reference
In-Depth Information
Layers of
sedimentary
rock
Compression
Compression
Limb
Compression
Compression
Monocline
Syncline
Anticline
Overturned
Overthrust
fault
(a)
(b)
(c)
Figure 13.12 The folding process.
(a) The vast majority of rocks lithify within horizontal beds. If these rocks are subsequently com-
pressed by plate collision, they are deformed in some way. In many places, folded rocks are associated with mountains and valleys.
(b) Folds in a rock outcrop in the United Kingdom. These rocks were once horizontal but have been bent in several different directions by
compressional forces. (c) The Comb Ridge Monocline near Mexican Hat, Utah. Compressional forces produced a single fold here that con-
nects two beds of relatively horizontal sedimentary rock. One of these beds of horizontal rock is on the top of the mountain, whereas the
other underlies the landscape in the foreground.
